Are consumption of dairy products and physical activity independently related to bone mineral density of 6-year-old children? Longitudinal and cross-sectional analyses in a birth cohort from Brazil.

Change log
Bielemann, Renata M 
Dos S Vaz, Juliana 
Domingues, Marlos R  ORCID logo
Matijasevich, Alicia  ORCID logo
Santos, Iná S 

OBJECTIVE: To evaluate cross-sectional and longitudinal associations of consumption of dairy products and physical activity (PA) with bone mineral density (BMD). DESIGN: Cohort study with children from the 2004 Pelotas (Brazil) Birth Cohort. SETTING: Pelotas, a medium-sized Brazilian city. SUBJECTS: The study started in 2004 and mothers/children were interviewed/measured periodically from birth to age 6 years. PA was measured by maternal proxy at 4 and 6 years and by accelerometry at 6 years. Consumption of dairy products was measured using 24 h food recall (at 4 years) and FFQ (at 6 years). Total-body and lumbar-spine BMD (g/cm2) were measured by dual-energy X-ray absorptiometry. RESULTS: At 6 years, BMD was measured in 3444 children and 2636 children provided data on objectively measured PA by accelerometry. Consumption of dairy products at 4 years was associated with higher lumbar-spine BMD at 6 years in boys, while current consumption was positively associated with BMD in both sexes (P < 0·001). PA assessed by maternal report at 4 and 6 years of age was associated with higher BMD at 6 years in boys. PA assessed by accelerometry was positively related to total-body and lumbar-spine BMD in boys and lumbar-spine BMD in girls. We did not find evidence for an interaction between PA and consumption of dairy products on BMD. CONCLUSIONS: We observed positive and independent longitudinal and cross-sectional associations between consumption of dairy products and PA with BMD in the total body and at the lumbar spine in young children.

Bone density, Child, Dairy products, Eating, Exercise, Absorptiometry, Photon, Accelerometry, Bone Density, Brazil, Child, Cross-Sectional Studies, Dairy Products, Exercise, Female, Humans, Male
Journal Title
Public Health Nutr
Conference Name
Journal ISSN
Volume Title
Cambridge University Press (CUP)